This invention is directed to the field of transferring information in two-dimensional form. The form may be an image or may be printed word. The information is converted to a digital bit map. The bit map information is compressed by any compression technique (JPEG, MPEG, WAVELET, FRACTAL, etc.) and at the same time a first forward error-correcting code is generated of the bit map. The compressed information and the first forward error-correction code is formed into data packets. These packets are transmitted with a second forward error-correcting code of the packet in order to correct any transmission errors. After correcting any transmission errors found at the receiving end as a result of the second forward error correction code, the data stream is decompressed, and an image bit map is regenerated. The first forward error-correction code is applied, and the bit map is corrected. This data bit map is converted to be compatible with the receiving equipment format so that it can be displayed optimally by the receiving equipment.
The transfer of image data on a wire or RF data link is limited by the size of the data file and the digital data transfer transmission capability of the data link. An increase in data capacity over a data link can be achieved by compression of the data stream file size. However, decompression of the data stream often produces errors in the image due to the compression/decompression processes. Error-correction information can be generated and transmitted along with the compressed data, but unless the error-correction information is almost as great as the reduction in size due to compression, errors may occur during the transmission.
There is need for a high-speed image transfer system which compresses bit map data using psycho-visual limitations so the parts of the image which are lost by the compression will not be visually detectable. Thus, upon decompression and correction, no visually useful information is lost.
In order to understand this invention it can be stated in essentially summary form that it is directed to a system which provides high speed image transfer. The information is converted to a digital bit map. The bit map information is compressed and at the same time a first forward error-correcting code is generated of the bit map. The compressed information and first forward error-correcting code are formed into data packets that will be transmitted. A second forward error-correction code is generated for the packets and is transmitted along with the packets. The received packets and second forward error-correction code will be used for correcting any transmission errors. After correction, the data stream is decompressed, and an image bit map is regenerated. The first forward error-correction code is applied to compensate for compression errors, and the bit map is corrected. This data bit map is then converted to the resolution of the receiving equipment format so that an optimum display of the input data is delivered to receiving equipment.
It is a purpose and advantage of this invention to provide a high-speed image transfer system by which an image is compressed to a minimum value by using psycho-visual limitations.
It is another purpose and advantage of this invention to provide a high-speed image transfer system using a first forward error-correction coding on a bit map of the image so that, after the bit map image is compressed and decompressed, the decompressed image can be restored to its visually useful original value.
It is another purpose and advantage of this invention to adjust the output display of the bit map image to correspond to the resolution of the output equipment to which it is delivered.
Other purposes and advantages of this invention will become apparent from the following portion of the specification and the attached drawings.